A standard armor panel of the kind to which the present invention refers, comprises a multitude of layers, designed to gradually absorb the kinetic energy of an impact, delivered to the panel by the incoming projectile and finally to avoid complete penetration of the projectile or its fragments through the armor. It can also stand against mechanical impacts of the plate.
The layers used in such armor panels may be divided into two groups: hard layers, e.g. steel or ceramic, and soft layers, e.g. Aramid or UHMW HDPE (Ultra High Molecular Weight High Density PolyEthylene). The harder layers are usually positioned facing the incoming projectile and absorb most of its kinetic energy, thereby slowing it down and shattering and/or deforming it substantially. The softer layers absorb the remains of the kinetic energy of the projectile, stopping it, and preventing it or its fragments from deforming/coming in contact with the body to be protected or at least from penetrating it.
The choice between various materials that may constitute the hard and/or soft layers of the armor panel is affected by the required end properties of the panel, such as ballistic properties, weight, etc. Thus, for example, a hard ceramic layer may be light-weight, yet brittle, while a hard steel layer having similar ballistic properties, may be very heavy, though easy to work with.
One example of an armor panel of the kind to which the present invention refers is disclosed in U.S. Pat. No. 6,389,594 to Israel Military Industries Ltd, which discloses an antiballistic article including a monolithic ceramic plate, an antiballistic backing material affixed to the ceramic monolith, and an outer shell formed of an antiballistic material, including a curable resin, enclosing the backing and ceramic monolith. The panel is produced by arranging the ceramic monolith and antiballistic backing inside the shell, immersing the shell in resin and then subjecting the entire structure to high temperature and pressure, due to which the resin is cured. After curing, the temperature is reduced letting the armor panel cool down, and afterwards the pressure is reduced, leaving the ceramic monolith “arrested” within the outer shell.